2. Western Uplands (WU)
2.3 Low elevation plateaux (Tablelands)
|Occurrences of the eastern Dundas Tablelands within the Wimmera CMA region include plains between Cherrypool and Brimpaen along with gently undulating plains at Telangatuk East. The plains fall either side of the western Black Range and as such represent part of a once expansive Neogene plain.
The eastern part of the Dundas is an undulating to rolling landscape of plains and rises that is underlain by Palaeozoic and Mesozoic rocks including Rocklands Rhyolite. Neogene deposits of Parilla Sand are superimposed over these older rocks while more recent fluvial deposits mask most of the plains. These plains and rises differ significantly from the western Dundas Tablelands due to the relative low relief of the landscape, lower drainage density but also the limited incision and dissection within the landscape. Slopes are level to gently inclined depending upon position in the landscape. Plains and rises extend southwards to form part of the greater Dundas Tablelands.
Overlying Cainozoic deposits are noted for their deep regolith profiles with kaolinitic saprolite and strong cementation of ferromanganiferous nodules (ferricrete) in the upper profile resulting in texture contrast soils. Stream incision of the peneplain is not as severe as the western Dundas Tablelands with slopes for gentle and valleys rolling rather than entrenched on the western Dundas Tablelands.
Vegetation of these slightly undulating slopes is largely savannah woodlands with Red Gums scattered throughout the landscape.
Soils are similar to those on the high relief low density tableland (2.3.1) being gradational to texture contrast soils with sandy surfaces and heavy subsoils (Dermosols, Chromosols). Ferricrete and ferruginous segregations (buckshot) are common as is the distinctive red and pale grey ‘tiger mottling’ that is representative of these Neogene regolith profiles. Grey (occasionally brown and black) cracking clays (Vertosols) may also occur in the depressions and on level plains.
Wetlands of these plains that also supply water to the Rocklands Reservoir occur south of Brimpaen. Savannah wetlands that are subject to periodic waterlogging provide habitats to many forms of fauna seasonally. Salinity is also a major issue where exposed in drainage depressions often as discharge sites with highly acidic conditions resulting in precipitation of acid sulphate minerals.
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